The present invention is generally related to recording systems for digital video and other data, and in particular, provides an adjustable ramp for transferring a read/write head to and from a spinning recording surface.
Video Cassette Recorders ("VCRs") dominate the consumer video market, due in part to their combination of low cost and recording capabilities. VCR analog magnetic tape recording cassettes can be used to record, play-back, and store video images in a format which is well adapted for use with existing analog television signals. The ability to record allows consumers to use the standard VHS VCR to save television shows and home movies, as well as for play-back of feature films.
The structure of VCR systems and recording media are adapted to record and archive existing television signals. Specifically, a large amount of analog data is presented on a standard television screen during a standard length feature film. VCR systems record this analog data using analog tape recording media. The VCR tape cassettes can be removed from the recording/play-back equipment for storage, thereby minimizing the system costs when large numbers of movies are stored.
While VCR systems successfully provide recording and archive capabilities at low cost, these existing consumer video systems have significant disadvantages. For example, accessing selected portions of a movie stored on a VCR tape can be quite slow. In particular, the cassette must be rewound to the beginning of the movie between each showing, which can involve a considerable delay. Additionally, transferring data to and from the tape takes a substantial amount of time. There has been little incentive to provide high speed accessing and transfer of the video data, as movies are typically recorded and played by the consumer in real time. Alternatives providing faster access are commercially available (for example, optical video disks), but these alternatives generally have not been able to overcome the VCR's low cost and recording capabilities.
Recent developments in video technology may decrease the VCR's advantages over alternative systems. Specifically, standard protocols have recently been established for High Definition TeleVision ("HDTV"). Although digital video cassette tapes are already available, the amount of data presented in a single HDTV feature film using some of the new protocols will represent a substantial increase over existing digital VCR system capacities. Optical disks may be able to accommodate these larger quantities of digital data. Unfortunately, despite many years of development, a successful low cost optical recording system has remained an elusive goal.
Personal computer magnetic data storage systems have evolved with structures which are quite different than consumer video storage systems. Modern personal computers often include a rigid magnetic disk which is fixed in an associated disk drive. These hard disk drive systems are adapted to access and transfer data to and from the recording surface at high speeds. It is generally advantageous to increase the total data storage capacity of each hard disk, as the disks themselves are typically fixed in the drive system. Hence, much of the data that is commonly used by the computer may be stored on a single disk.
The simplicity provided by a fixed disk drive system helps maintain overall system reliability, and also helps reduce the overall storage system costs. Nonetheless, removable hard disk cartridge systems have recently become commercially available, and are now gaining some acceptance. While considerable quantities of computer data can be stored using these removable hard disk cartridge systems, their complexity, less than ideal reliability, and cost has limited their use to selected numbers of high-end personal computer users.
One particular disadvantage of known removal hard disk cartridge systems is the high cost of the tight tolerance structural components of the disk drive. More specifically, the read/write heads of the disk drive are usually retracted during insertion and removal of the cartridge, and a head load ramp may be used to transfer the head between the retracted position and a data transfer zone along the recording surface. Unfortunately, the arm actuation mechanism, spindle drive motor, and head load ramp are often distributed widely across the housing structure. To maintain the required alignment between these components, known removable hard disk drive housings generally include a machined base structure. These large, accurately machined structures add significantly to the overall cost of the recording system.
In light of the above, it would be desirable to provide improved systems, devices, and methods for storing digital video and other data. It would be particularly advantageous if these improvements were adaptable for use with both video systems and computers, especially if they could be produced and assembled at a lower cost than known removal hard disk systems.